The Monkey King was persuaded by Guanyin to become the Tang Priest's apprentice, so he jumped out from the bottom of two mountains, made four obeisances to Tang Priest and became his master.
Bajie was also an apprentice who was persuaded by Guanyin to become a monk. He set up a incense table in Gaolaozhuang, and worshipped Tang Priest as his teacher. The original text said that "the advanced is the younger brother", so the Monkey King was worshipped as the younger brother.
Friar Sand was also persuaded by Guanyin to become a disciple of Buddhist scriptures and converted to Buddhism. It was the Tang Priest who gave birth to Friar Sand. After paying homage to Master, Friar Sand paid homage to Wukong and Bajie, and divided the sizes.
However, when the original Yulong met Guanyin, it was hanging in the sky and would be executed in a few days. It was Guanyin who went to the Jade Emperor to intercede and wanted Yulong to do enough for Buddhist scriptures. The Jade Emperor pardoned Yulong's death sentence and gave it to Guanyin. Yulong feels that the Buddha is alive and is willing to listen to the words of the Bodhisattva and do his best for the Buddhist scriptures.
Guanyin doesn't want Yulong to be the Tang Priest's apprentice, but should be the Tang Priest's foot strength, that is, just like a servant. When Tang Priest saw Yulong, Yulong had turned white. The news of Guanyin was given to Tang Priest by the Monkey King. Tang Priest didn't treat Bai as a human being, but as a foot. And Bai just tried his best, never confronting the Monkey King's other disciples and monsters. The monsters tried to catch it, but it didn't resist, so they let it go into the cave.
Bai never worshipped Tang Priest as a teacher, nor did he worship Wukong, Bajie and Friar Sand as brothers.
However, in Baoxiangguo, when the Monkey King was expelled from Huaguo Mountain, Pig Bajie and Friar Sand were defeated by monsters, Tang Priest was turned into a tiger, and the great cause of learning Buddhist scriptures was about to die, he called Pig Bajie his senior brother in vain and begged Pig Bajie to ask him to subdue the demon. He is called Bajie by his brother because he thinks he is a younger brother, out of courtesy and respect. Although he joined the Buddhist scripture group earlier than Bajie, he did not learn from the teacher, so he called Wukong, Bajie and Friar Sand "brothers".